Tuesday, December 24, 2013

Shopping for a science geek or a budding genius doesn’t have to be difficult. Whether it’s a gift for the holidays, a birthday, graduation, or a reward for a job well done, here is a list of the top 10 gifts for science geeks to help you give the perfect gift for that special someone on your mind.

The Science Chef Cookbook contains instructions for 100 edible experiments and recipes that teach kids science basics such as how yeast makes dough rise and what makes popcorn pop. As much fun to learn as it is to eat!

A Static Electricity Eliminatoris a great gift for anyone who is constantly getting zapped due to static. The Eliminator is an especially great gift for computer techs who are constantly rebuilding or repairing computers.

Friday, December 20, 2013

Tuberculosis (TB) is caused by a bacteria called Mycobacterium tuberculosis. The bacteria typically attacks the lungs, but TB bacteria can attack any part of the body such as the kidneys, spine and even the brain.

Tuberculosis is spread through the air from one person to another from coughing, sneezing, speaking or singing. People nearby breathe in these bacteria and become infected. Not everyone infected with TB bacteria will become sick however. Tuberculosis bacteria can live in the human body without making a person sick for years.

Treatment of TB uses antibiotics to kill the bacteria. Effective treatment can be difficult due to the unusual structure and chemical composition of the mycobacterial cell wall. This cell wall hinders the entry of drugs and makes many antibiotics ineffective.

Wednesday, December 18, 2013

Why would a biologist prefer a phase contrast microscope over a standard brightfield microscope? Here are a few reasons why phase contrast microscopes are preferred by many biologists over a variety of other microscopes available to them.

Cheek cells - phase contrast

Cheek cells - brightfield

The images shown above are both of the exact same slide of human cheek cells. The image shown at left was captured with brightfield and the image at right was captured with phase contrast.

A phase contrast microscope allows viewing a clear (transparent) specimen - a living cell - without staining the specimen, which effectively kills it, thereby eliminating the time consuming process of staining the specimen. This is preferred by biologists since living cells can be studied during cell division.

Light passing through a clear specimen undergoes phase changes, brightening areas of the specimen that creates a contrast against the darker areas. This contrast of light and dark makes the specimen visible to the human eye. This is important to biologists because the light contrasts with various mechanisms of the specimen, such as the membrane, cilia and flagella, against a lighter/darker background, making them visible under the microscope. Of importance in molecular biology, the phase contrast microscope enables biologists working in such fields as cancer research and developmental biology to distinguish one type of cell from another.

Phase contrast microscopes are capable of 50x to 1000x magnification. Such magnification is important to biologists because it allows visibility of activities at the cellular level such as protein motility, autography, cell signaling, and metabolism thereby broadening our understanding of cells.

A phase contrast microscope can be used for brightfield, (often darkfield) and phase contrast. Whereas a brightfield microscope can typically only be used for brightfield work.

Differences between a phase contrast microscope and a brightfield microscope.

Monday, December 16, 2013

Bacillus is a rod-shaped bacterium. Bacilli are an extremely diverse group of bacteria that include both the causative agent of anthrax (Bacillus anthracis) as well as several species that synthesize important antibiotics. In addition to uses in the medical field, bacillus spores, due to their extreme tolerance to both heat and disinfectants, are used to test heat sterilization techniques and chemical disinfectants.

Bacilli are also used in the detergent manufacturing industry because of their ability to synthesize important enzymes.

Bacilli are rod-shaped. Each bacterium only creates one spore, which is resistant to heat, cold, radiation, desiccation (extreme dryness), and disinfectants. Baccilli are capable of living in a wide range of habitats, including many extreme habitats such as the desert and the arctic.

Bacilli can cause infections ranging from ear infections and meningitis to urinary tract infections. They mainly occur as secondary infections in immunodeficient or compromised hosts. The most well-known disease caused by bacilli is anthrax. Antrax dates back many years, as it is assumed that the fifth and sixth plagues recorded in the Bible were anthrax (the fifth attacking animals and the sixth attacking humans). Anthrax in recent time has been brought into the public eye by being used for bio-terrorism.

There are three ways humans can contract anthrax: (1) Cutaneous anthrax occurs when contact with spores from dust particles or through an abrasion. (2) Gastrointestinal anthrax is contracted by ingesting contaminated meat. (3) Pulmonary anthrax results after inhaling spores that are transported to the lymph nodes where they multiply.

Bacillus captured at 1000x magnification without use of immersion oil.

Friday, December 13, 2013

Have you ever wondered how the inner components of a digital camera or computer could be manufactured with extreme precision? Such precision requires the use of a measuring microscope.

Measuring microscopes are excellent tools used in research and development, tool making, and industrial manufacturing for precision measurements of 2D and 3D parts, angles, shapes, linear dimensions, screw threads, and diameter of objects, including holes that are too small for a measurement probe. Quality control and quality measurement are key steps in the manufacturing process and measuring microscopes are used extensively during this process. Measuring microscopes are also necessary for inspecting a variety of objects such as semiconductors, electronic and electrical components, precision components, resin moldings, and medical products, making it possible to measure specimens that are too soft for contact measurement.

Measuring microscopes provide high power magnification and because the reflected light is pumped in through the objective lenses, opaque objects can be viewed. Some measuring microscopes also offer transmitted light from beneath the stage. The stage contains working room for larger objects, and the digimatic indicators allow for making measurements.

Measuring microscopes can measure up to 1/2 of a micrometer. Larger measuring microscopes are suitable for the following applications:

Length measurement in Cartesian and polar coordinates.

Angle measurements of tools such as threading tools, punches, and guages.

Thread measurements such as profiling major and minor diameters, height of lead, thread angle, profile position with respect to the thread axis and the shape of the thread.

Comparison of centers with drawn patters and drawing of projected profiles.

Verification of surface finish.

Measurement of surface defects.

Measurements of hardness test indentations.

Known for its high magnification and suitability for shop use, measuring microscopes are well built for a variety of applications in the industrial market.

Wednesday, December 11, 2013

A mushroom is a fleshy, spore-bearing fruiting body of a fungus. The term mushroom describes a variety of gilled fungi, with or without stems. The gills are seen below in detail (blue).

Photo: Captured in Strouds Run State Park, Athens, Ohio USA by Dan Molter

The terms "mushroom" and "toadstool" go back centuries and were never precisely defined. Toadstool was often a term applied to poisonous mushrooms or to those that have the classic umbrella-like cap and stem form. In German folklore and old fairy tales, toads are often depicted sitting on toadstool mushrooms and catching flies.

Gifts for Younger Kids (Ages 3-5)

Younger kids are often very interested in science, but they can't yet quite wrap their head around cells and biological specimens that can not be seen by the naked eye. However, they do love to look at things they are already familiar with such as flowers, rocks, toys from around the house, a dollar bill, etc. The MW1-L1 microscope provides 20x magnification and needs no light, cord, or batteries for operation. The single eyepiece is perfect for young kids to look through (rather than some binocular microscopes where the eyepieces can be too far apart for young children).

Gifts for Elementary School Kids (Age 6-11)

Elementary school age kids find it fascinating to look at microscope slides or Protozoans swimming in pond water. It can be a bit tricky for kids of this age to prepare their own slides, so prepared slides are usually the best route when starting off with a high power microscope for Elementary school age students.

High School students will have biology classes and can integrate their microscope into school work. A digital microscope allows them to view live images on the computer and capture and save images. The included software can make measurements as well.

Gifts for Hobbyists

Recommendation: A stereo microscope with magnification somewhere between 10x-40x is best for viewing stamps, coins, collections, etc.

Hobby microscopes allow the user to look at small parts or collections. Model railroaders or model builders paint small pieces and glue together parts. Stamp and coin collectors will want to examine dates and defects. Needle-pointers want to view small stitches. All of these hobbyists will do best with magnification somewhere in the range of 10x-40x. A dual power microscope with 10x and 30x is less expensive than a zoom microscope.

Thursday, December 5, 2013

The Thyroid Gland is a butterfly-shaped gland that resides on the lower front of the neck, just below the Adam's apple. When the thyroid is a normal size it can't be felt in the human body. The thyroid is full of blood vessels and its main job is to secrete several hormones called Thyroid Hormones. These act throughout the body to influence metabolism, growth and development, and body temperature.

The thyroid gland covers the windpipe from three sides. The thyroid gland produces hormones T3 and T4, which help the body to produce and regulate adrenaline, ephinephrine, and dopamine (all of which are active in brain chemistry). Without a functional thyroid, the human body can not break down proteins or process carbohydrates and vitamins. Thyroid gland problems often lead to weight gain.

Image courtesy: WebMD

The Thyroid gland can not produce hormones on its own. It requires help from the Pituitary gland. The Pituitary gland produces a thyroid stimulating hormone.

The thyroid gland is one of the largest endocrine glands and gets its name from the Greek adjective for "shield shaped" because of its shape relative to the thyroid cartilage.

In the human thyroid gland image above the follicles are labeled with "X". These are the follicles that selectively absorb iodine from the blood for production of thyroid hormones. 25 percent of the body's iodine ions are in the thyroid gland.

The follicular epithelial cells are labeled "Y". The follicles mentioned above are surrounded by a single layer of thyroid epithelial cells which secrete T3 and T4 hormones. When they are not secreting hormones, the epithelial cells range in size from low columnar to cuboidal cells. They are much taller columnar cells when active.

The endothelial cells (very small) are labeled with "Z". These cells are scattered among follicular cells and are found in spaces between spherical follicles. Their primary role is to secrete calcitonin, which acts to reduce blood calcium.

The above image of a human thyroid gland was captured at 1000x magnification. A 100x oil immersion objective was used, however immersion oil was not used when capturing the image (hence the lack of crispness in the image). Whenever using a 100x oil immersion lens, the best microscopy images will always be obtained when using immersion oil.

Monday, November 25, 2013

Motor neurons are located in the central nervous system and are used to control muscles. Motor neurons carry signals from the spinal cord to the muscles to produce movement. Several categories classify motor neurons.

Somatic Motor Neurons - These originate in the central nervous system and project their axons to the target tissues, which are always skeletal muscles (involved in locomotion). Somatic motor neurons are involved in muscles that move limbs, abdominal or intercostal muscles.

Specialized Viceral Motor Neurons - These motor neurons directly innervate branchial muscles, such as gills in fish, muscles in the face and neck in land vertebrates.

Tuesday, November 19, 2013

Sheep and goat fecal analysis is an important component for goat farmers with worm and Coccidia infestations. Animal breeders including horses, rabbits, cats, dogs and cattle may also have these same issues. Worm and Coccidia parasites alone kill more goats than all other illnesses combined. A regular established program of microscopic examination of goat "pills" (feces) can help farmers find and treat parasites before they kill many of the animals.

Coccidia is a protozoan parasite. This protozoan causes Coccidiosis, which can be one of the most devastating diseases to livestock, particularly among young kids. Coccidiosis causes watery diarrhea that is sometimes bloody and can be life-threatening to young animals. The presence of Coccidia in the intestines does not mean the animal is actually suffering from Coccidiosis. The protozoans only cause disease when their numbers become so great that damage is caused to the host. The image above is Coccidia during the infective stage. The oocyst contains two sporocysts.

Test tube holding rack (you can use a styrofoam block with holes punched in it)

Fecal Analysis Procedure:

Mix up the flotation solution (it should be saturated, so you want to dissolve as much solid in the water as it will hold). Saturated salt solution requires a pound of salt in a little under 5 cups of water. Collect fresh feces using a small jar for each animal. Be sure to label with the date, time and animal. Place 3-4 goat pellets into a test tube and pour in just enough flotation solution to cover them. Stir and mix well with the stir stick. Strain with the cheese cloth to remove large particles and pour the strained liquid into a clean test tube. Fill up the test tube with more liquid so it reaches the very top. Place a cover slip over the top of the test tube and wait 30 minutes. Over time the eggs will float up to the top and adhere to the glass plate.

Carefully remove the cover slip and lower it at an angle over a microscope slide with the sample between both pieces of glass. Examine the specimen for worm eggs and Coccidia Oocysts. Start with the lowest magnification (40x) on the microscope and move up to 400x and if you have it, 1000x.

You should be able to identify Coccidia Oocysts, Nematode Eggs and Taperworm eggs. When performing a fecal count a general guide is that a level of about 500 eggs per gram of feces would indicate a next step of worming. If a regular testing system is in place (every 4-8 weeks is ideal) the best indication is when there is a dramatic increase in egg counts.

Thursday, November 14, 2013

When do you need a metallurgical microscope versus a stereo microscope? Both of these types of microscopes offer reflected illumination, which means light will shine down from above the object, which makes it possible to view opaque specimens.

Stereo microscopes will typically offer anywhere from 7x-50x magnification - which is a relatively low magnification. At 40x magnification your field of view is made up of 5mm. If you need to view micron size particles you will need a metallurgical microscope.

If you have a solid object that does not allow light to pass through it, you will need either a stereo microscope or a metallurgical microscope in order to view your specimen in depth. Which microscope you need depends on the size of the particles you wish to view. Keep in mind that more magnification is not always better since it does reduce your overall field of view.

Step #1

Fill each vase or cup about 1-2 inches full of water and add some food coloring until the water is dark. Once you have five vases filled with colored water, place the stems of five carnations each in a different vase of colored water.

Step #2

Take the final white carnation and look at the petals under the stereo microscope. What do you notice? Draw a picture of the structure of the petal as seen under the microscope.

Step #3

How long did it take for your flowers to soak up the food coloring into the petals? If you are preparing a presentation for your science class include this information in your report. Take one petal off of each different colored flower and look at it through your microscope. Can you see the route that the flower used to "drink up the water" and how the color seeped into the petals? Unlike humans, flowers do not have kidneys to filter out the food coloring so the petals simply change color when they are placed in colored water. If you would like to share the colored flowers with your class, they will remain colored even once you remove them from the water.

Monday, November 4, 2013

Biological microscopes provide high magnification and optimal resolution is key to viewing a high quality image. Follow these tips in order to achieve the best possible resolution from your light microscope.

Wednesday, October 30, 2013

Microscope World recently posted on our most popular high school biology microscopes and in turn were asked about the most popular high school dissecting microscopes. This post is dedicated to high school dissecting microscopes and will break down the benefits and downsides of the different microscope options.

Basic / Cost Effective:

The most popular and cost effective high school dissecting microscope is the MW3-LED1B cordless dual power microscope. This dissecting microscope is popular among high schools because it is simple, it is cordless, and it is affordable (under $300). The microscope has two magnifications, the most popular model sold has 10x and 30x magnification. Eyepieces can be swapped out for alternative magnification. A few downsides of this microscope are the smaller working surface and the inability to raise the head of the microscope higher to increase working space for larger specimens.

The S2-BL microscope is another dual magnification (10x and 30x) dissecting microscope, but on a post stand, which allows the microscope body to be moved up higher on the stand, accommodating larger specimens beneath the microscope. The LED ring light provides a brighter light than the lights that are built into a microscope stand, and the larger base provides more working surface for placing frogs, plants or whatever biology class presents for the lesson plan.

Advanced Dissection:

The S6-BLED10 stereo zoom dissection microscope offers 7x-46x zoom magnification. Rather than two set magnifications, students can view every magnification within a range. Two LED lights can be operated together or separately.

Digital Options:

The S2-PLCD digital dissecting microscope is popular in high schools because it can reduce the number of microscopes required in a classroom thanks to the LCD camera. Rather than having a microscope for each student, some schools have a microscope with a tablet camera that allows multiple students to view the specimen without each having to look through the microscope. The Android tablet camera is popular, as it is a regular Android tablet touch screen that attaches to the microscope. The touch screen is easy to use and images can be captured and saved, emailed or included in reports. At under $800, this digital LCD 10x/30x dissecting microscope is attractive for schools that need to stay within a tighter budget.

The S2-TPD dissecting digital microscope is priced under $700 and offers 10x/30x magnification along with a 3mp USB camera that allows projection of images to a monitor or computer. Images can be captured and saved, emailed or placed in reports.

Monday, October 28, 2013

Setting up the ideal environment in a laboratory for microscope use is a fairly simple process. Follow these guidelines to obtain the best resolution when using your microscope as well as prolong the life of the instrument.

Don't work in a dimly lit room in order to better "see" microscope images.

If possible have the lab setup include windows with daylight for ideal image resolution.

If windows are not available, use overhead lighting in the lab.

Use a microscope with an illuminator that emits bright light with a color temperature approaching that of "daylight". Neutral filters can be used to control illumination intensity.

Clean dust off of eyepieces, objectives and condensers. Determine where the dust particles are located by rotating the eyepiece, the objective or the condenser. If the dust is on the particular microscope part, when you rotate it the particle will move in the field of view.

Wednesday, October 23, 2013

Fluorescence microscopy is a technique used to study specimens that can be made to fluoresce. Certain specimen materials emit energy detectable as visible light when irradiated with the light of a specific wavelength. The sample might be fluorescing in its natural form, or it can be treated with fluorescing chemicals.

A fluorescence microscope lets excited light radiate the specimen and then sorts out the much weaker emitted light that makes up the image. The fluorescence microscope has a filter that only lets through radiation with the desired wavelength that matches the material that is fluorescing. The radiation collides with the atoms in the specimen and electrons are excited to a higher energy level. As these atoms relax to a lower level, they emit light. In order to become visible, this emitted light is separated from the much brighter excitation light in a second filter. The fluorescing areas can be observed in the microscope and shine out on a dark background with high contrast.

The mechanical stage on the stereo microscope that allows reflected light to pass through the stage.

Plastic Film captured with transmitted light under the stereo microscope.

Images were captured both with transmitted and reflected light under the stereo microscope. The measurement software included with the microscope camera was used to measure the diameter of the hole in the plastic film.

Plastic Film captured with reflected light under the stereo microscope.